// run: $exec < input
#include <iostream>
#include <iomanip>

int const maxn = 2007;

double poss[maxn][maxn];
int n, t;
double p;

int main()
{
	std::cin >> n >> p >> t;
	poss[n][0] = 1;
	for (int i = 1; i <= t; i++) {
		poss[0][i] = poss[1][i - 1] * p + poss[0][i - 1];
		for (int j = 1; j <= n; j++) {
			poss[j][i] = poss[j + 1][i - 1] * p + poss[j][i - 1] * (1 - p);
		}
	}
	double ans = 0;
	for (int i = 0; i <= n; i++)
		ans += (n - i) * poss[i][t];
	std::cout << std::fixed << std::setprecision(7) << ans << '\n';
}

